<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>边框</title>
    <style>
        div{
            /*border-bottom: 1px solid red;*/
            width: 100px;
            height: 100px;
            border: 1px solid red;
            /*圆角,值越大 越圆 超越宽高一般为正圆*/
            border-radius: 100px;


        }

    </style>


</head>
<body>
<div>边框测试</div>




</body>
</html>